F. T. Brooks 
several parts of the country. It is, however, only in the few estates 
where groups of trees have been killed by it that serious damage 
has yet been done by this fungus. 
As the fungus progresses in the collar and root system of the 
tree, the foliage becomes thin and the branches commence to die 
back ; the tree gradually dies unless successfully treated in an early 
stage of attack. 
Fructifications of the fungus appear on dead tissues of the 
collar and exposed roots of affected trees to which they are usually 
closely adpressed. The fruit-bodies, which were found on several 
occasions on diseased rubber trees in various parts of the country 
towards the end of 1914, are plate-like in form and grey brown to 
blackish in colour. The fructifications are easily overlooked, 
especially in the earlier stages of development, for the colour is not 
unlike that of the soil on many estates. The difficulty of distin¬ 
guishing the fungus is further increased in wet weather because the 
fructifications developing near the ground become splashed with 
mud. Fig. 2 shews a fruit-body which was taken from a diseased 
Fio. 2. Ustulina zonata. Photograph of a fructification of Ustulina zonata 
obtained from the base of a rubber tree. 
rubber tree. Fig. 3 is a photograph of the base of a diseased rubber 
tree bearing a fructification (/) of Ustulina zonata at about soil 
level. The tree has been opened up in order to show the limits of 
diseased and healthy tissues (D and H respectively) above the 
collar. 
